Process for the treatment of fruit for the prevention of decay



Patented. Mar. 24,1931

UNITED s'rmas PATENT OFFICE HARRY R. FULTON JOHN J. BOWMAN, OF WASHINGTON, DISTRICT OF COLUMBIA PROCESS FOR THE TREATMENT OF 'FRUIT FOR THE PREVENTION OF DEG AY Ho Drawing.

Application filed November 19, 1927. Serial No. 284,545.

(GRANTED UNDER THE ACT OF MARCH 3, 1883; 22 STAT. I, 625) This application is made under the act of March 3, 1883, chapter 143, (22 Stat. 625) and the invention herein described and claimed ma be used by the Government of the United tates or any of its oflicers or emloyees in the. prosecution of work for the overnment, or any personsin the United States, without payment to us of any royalty t ereon.

This invention consists of a process of treating fresh fruit, particularly citrus fruit, with an aqueous solution of certain salts of "manganese in which manganese is combined with a strong acid, such as manganese chloride and manganese sulphate, to prevent stem end rot and decay caused by green and blue molds and other organisms. Effective control of rots may be obtained by using manganese sulphate or manganese chloride in concentrations ranging from" about one per cent to about five per cent by weight of solution. In place of chemically pure salts it has been found that the ordinary technical or com mercial grades of these materials can be substituted when proper allowance is made for their degree of purity.

Treatment "with these materials controls stem end rot caused by Phomopsz's oz'trz' and Diplodz'a natalensz's, and aids .m control of other decays such as blue mold rot caused by Pem'oz'ZZz'um z'talz'cmn and green mold rot caused by Pem'oz'llz'um digitatum.

Wedo not desire to limit the temperature" of the treating solution to any set temperature as various degrees from 60 F. upward have proved effective. The time required for treatment with this fun 'cide necessary to prevent decay caused \by t ese fungi depends to some extent upon the age and condition of the fruit. For young and vigorous fruit, a thorough wetting of the rind,- which can be done in less than one minute, is sufiicient to give efiective control, while overripe fruit may require as much as ten minutes treatment to render the tissue of the rind resistant to the fungi.

We'do not limit the strength of solution strictly to the proportions stated, but in general practice it has been found useful to employ a concentration within the stated range.

"a manner that the entire surface For practical purposes we prefer to use manganese sulphate in a 5 weight, and the manganese chloride in a 1 percentsolution being more potent as a fungicide than the former and at the same time is likely to cause injury to the rind of citrus fruits if used in too strong solution.

The treatment above described is accomplished by spraving. submerging, immersing,

per cent solution bybyweight, the. latter material or causing the fruit to pass through a receptacle or tank containing the solution. insuch of the fruit is Wet with the solution. The apparatus de scribed by Barger. Hukill and Hawkins in the United States Patent No. 1,599,733 may.

machinery in be used for this purpose, or the ordinary usefor washing fruit in citrus fruit packing may be used with or without simple adaptations.

The treating solution may be applied to the fruit immediately prior to the time of washing the fruit, during the washing process. following the washing process. or as a treatment on clean fruit without other wash- Tn some cases it may be advisable to spray such fruit after it leaves the treating solution with the manganese compounds to dilute or remove the excess solution on the surface of the rind.

We claim:

' -1. A process for treating fresh fruits and vegetables with an aqueous solution of 'a salt of manganese in which manganese is combined with a strong acid, in strength sufficient to control blue-mold rot, stem-end rot and other forms of decay.

2. A process of treating fresh fruit, especially citrus fruit, with a solution of manganese sulphate iii-proportions of 1 part by weight to 10O parts solution up to 1 part by Weight to 20 parts solution, said solution being adapted to prevent'decay in such fruit caused by Phomopsz's m'tri, Diplodz'a natalen- 82's, Penicillz'mn italz'oum, and Penicillz'wm digital/um. I

3. A process of treating citrus fruit with an aqueous solution of manganese sulphate water, or with a weak solution of one ofcontaining approximately five per cent by weight of manganese sulphate at a temperature of not less than 60 F., to prevent green afind blue mold decay and stem end rot in such ruit.

4. A process of treating fresh fruit, e'specially citrus fruit, with an aqueous solution of manganese sulphate at temperatures below 130 F., at a concentration and for a period sufiicient to cause the fruit to become thoroughly wet with the solution, to prevent stem end rot and blue and green mold decay of such fruit.

5. A. process of treating citrus fruit for the A v prevention of stem end rot and blue mold rot or other forms of decay with an aqueous solution of manganese sulphate of vsufiicient strength to eflectively retard the development of said forms of decay, at temperatures commonly used for washing fruit, causing the fruit to remain in contact with the solution 1 from one to ten minutes, and further spraying the fruit after it leaves the treating solution to remove a largepart or substantially all of said solution from the surface of the fruit.

6. In the preparation of. fresh fruit for market a process which comprises subjecting a the fruit to the action of an aqueous solution of manganese sulphate and the subsequent removal of a large part or substantially all of said solutionfrom the surface of the fruit.

7. A methqd for the prevention of decayof fruits and vegetables consisting in the treatment of such articles with a solution comprising manganese. sulphate.

HARRY R. FULTON.

JOHN J. BOWMAN. 

